Supplementary Memorandum submitted by English Nature
(F 65)
As requested, following our oral evidence to the committee
on 17 June, I enclose, as Annex A, our joint paper on coastal
management prepared with the Environment Agency. The full title
of this is "Sustainable flood defence and habitat conservation
in estuaries—a strategic framework".
You also asked us to answer the following question:
"Could you specify for us the changes to PAGN you
have proposed to MAFF to ensure environmental features are properly
considered in the appraisal process? Have you developed new methodologies
to tackle the problem of valuing wetlands and their associated
wildlife? What response have you had from MAFF regarding possible
amendment of PAGN to take your requests into account?"
Our answer to this question forms Annex B to this letter.
In addition to these two specific pieces of information you
indicated that we may also submit a memorandum covering any additional
information which would help to illustrate the oral evidence we
gave. Whilst not wishing to overburden the committee with detail,
we feel there are a few points on which additional information
would be helpful. This memorandum forms Annex C to this letter.
Thank you for the opportunity to provide evidence to the
committee. I look forward to seeing the report.
26 June 1998
ANNEX A
SUSTAINABLE FLOOD DEFENCE AND HABITAT
CONSERVATION IN ESTUARIES—A STRATEGIC FRAMEWORK
Environment Agency and English Nature
PURPOSE
The Environment Agency and English Nature have a joint interest
in estuaries because the sustainable management of flood defences
and the conservation of inter-tidal habitats are indivisible.
This strategic framework recognises this interdependency and the
common goals shared by both organisations.
Why are Inter-Tidal Habitats Beneficial for Flood Defence?
Inter-tidal habitats, such as saltmarshes and mudflats are
of fundamental importance for flood defence by virtue of their
ability to absorb wave energy that would otherwise be dissipated
against the defensive structure. Indeed many flood defences have
actually been designed and built to make full use of the protective
value of saltmarshes and mudflats. The contribution that they
make to flood defence needs is often underestimated.
There has been a loss of saltmarsh and mudflat in estuaries
resulting from "coastal squeeze" and the disruption
of natural sedimentary systems. This has reduced the effectiveness
of flood defences and placed important wildlife habitats under
stress.
"Coastal Squeeze"
This is the name given to the process by which natural
coastal features are drowned or eroded away as they become trapped
between man-made sea defences and rising sea levels.
The loss of a saltmarsh fronting a defence will increase
the wave action directly attacking the defence and raise the risk
of failure. Costs of maintaining sea walls will increase from
the damage caused by the increased wave action.
Maintaining saltmarsh as an integrated part of a defence
will provide real financial benefit and an example is illustrated
in Table 1.
| TABLE 1
|
| Effectiveness of Saltmarshes in Coastal Defence
|
|
Width of Saltmarsh1
(m) |
Height of Crest Wall
(m) | Cost of Sea Wall
(£ per m)
|
|
| 80 | 3 | 1,400
|
| 60 | 4 | 1,500
|
| 30 | 5 | 1,800
|
| 6 | 6 | 1,500
|
| 0 | 12 | 5,000
|
|
1 Distance between toe of sea wall and seaward edge of saltmarsh.
Source: Environment Agency Anglian Region.
|
WHAT IS
THE ISSUE?
The Current Status of English Estuaries
Estuarine locations contain the longest lengths of flood
defence and the largest areas of inter-tidal habitats. The physical
outline of practically all English estuaries has been heavily
influenced by historical restrictions, most notably reclamations
for agriculture and industrial development.
Saltmarshes and mudflats are eroding due to coastal squeeze
and the main estuaries at risk are from the Humber southwards
and westwards to the Severn.
It is difficult to monitor the exact rate of change but current
losses are estimated at 125 ha per year.
Value of Inter-tidal Habitat
Estuaries contain a number of different types of wildlife
habitat, examples include saltmarsh, mudflat, sandflat and shingle
bars.
Saltmarshes are composed of a series of highly specialised
salt tolerant plant communities. The distribution of these communities
reflects differences in position in the tidal range gradations
of salinity, responses to management and geographical variations
in climate. The United Kingdom has a substantial proportion of
Europe's saltmarshes and so has a proportionate responsibility
for ensuring their conservation. In addition, many saltmarshes
and their associated inter-tidal mud and sand flats are recognised
by the Habitats and Birds Directives as habitats of European importance.
In consequence, many of these areas are designated as Special
Areas of Conservation (SACs) and Special Protection Areas (SPAs).
These Directives place similar obligations on member states to
ensure that conservation of these habitats and the bird populations
they support.
The value of inter-tidal habitats in nature conservation
terms is not easily quantified. A qualitative value may be determined
which is dependent upon the size and structure of the inter-tidal
habitat. An increase in the width of the saltmarsh and mudflat
will increase its value as a habitat.
Sustainable Development
The Environment Agency and English Nature are committed to
the Government's goal of furthering sustainable development. Flood
defence works are a key operational responsibility of the Environment
Agency where sustainable development principles can be directly
applied. In the context of flood and coastal defence, sustainable
schemes are defined in the Strategy for Flood and Coastal Defence
in England and Wales (MAFF/WO, 1993) as:
Schemes which take account of the interrelationships with
other defences, developments and processes within a catchment
or coastal cell, and which avoid as far as possible tying of future
generations into inflexible and expensive options for defence.
In the context of estuaries, it is critical to understand
the processes that are operating and how flood defences and other
structures have interacted with these processes to give the current
estuary shape. Sustainable development can be achieved by ensuring
that, where possible, flood defences are placed where they are
not going to interfere with, but ideally improve, the efficient
operation of the estuary system.
THE NEED
FOR A
STRATEGIC FRAMEWORK
A Strategic framework is required to ensure that the full
value of inter-tidal habitats is utilised for flood defence purposes
and to conserve and enhance the nature conservation resource.
Given this mutual interest in inter-tidal habitats it is logical
for the Environment Agency and English Nature to produce a joint
framework that embraces this shared need.
As part of its commitment to 1992 "Earth Summit"
in Rio the Government produced "The UK Biodiversity Action
Plan". This sets out how, as a nation, we will conserve and
enhance the variety and populations of plants and animals in the
country as a whole.
As part of the national Biodiversity Action Plan, further
detailed costed action plans are being prepared for a wide range
of habitats and species, including inter-tidal habitats such as
saltmarshes. A major aim of this framework is to play a guiding
role in the development of the saltmarsh plan as it will indicate
what is achievable in the long term.
From all points of view it is important that the process
of defining national biodiversity targets is consistent with the
aim of achieving sustainable estuarine forms. It is intended this
framework will inform the process of national biodiversity target
setting for intertidal habitats.
Following the launch of its "Campaign for a Living Coast"
in 1992, English Nature defined a target of 100ha per year of
saltmarsh habitat creation in England (based on estimated loss
rates at that time), in order to combat losses due to erosion
and maintain saltmarsh areas at 1992 levels. Since 1992 this estimate
has been refined and losses are now anticipated at 125ha per year.
Since then much progress has been made in understanding how
to create saltmarsh habitat. It has become clear that the 100ha
per year target is not currently achievable principally because:
— the location of habitat creation in estuarine
situations requires careful consideration through an understanding
of how the physical estuarine system works.
The refined target of 125ha of re-created saltmarsh per year
will initially serve as the benchmark to measure the effectiveness
of the framework. There will be a period of transition from this
"working" target to a new national target, based on
the known capacity of estuarine areas to sustain new habitat.
Such a framework needs to be realistic and achievable.
AIMS AND
OBJECTIVES
Such a strategic framework needs to be clear about what it
is seeking to achieve. The following aims and objectives are recommended.
Aims
1. To facilitate the sustainable management of intertidal
habitats for flood defence and conservation within estuaries.
2. To enable progress to be made towards the achievement
of national biodiversity targets in relation to inter-tidal habitats.
Objectives
1. To establish an appropriate technique for the determination
of the extent and rates of change of inter-tidal habitats.
2. To establish guidelines through which the Shoreline
Management Planning process in estuaries can determine the capacity
of individual estuaries to maintain and create inter-tidal habitats.
3. To promote targets for inter-tidal habitat creation
in estuaries based on the requirements of sustainable flood defence,
the capacity of the estuary to support such habitats and the need
to meet national biodiversity targets.
4. To establish a mechanism to determine the contribution
of Shoreline Management Plans in estuaries to national biodiversity
targets for inter-tidal areas.
THE WAY
FORWARD
English Nature and the Environment Agency, in partnership
with others, are committed to implementing this strategic framework
to achieve the goal of sustainable management of estuaries for
future generations. We will set up a joint group to implement
and monitor the objectives of the framework.
References
CCRU (1996). "Geomorphological Trends in the Blackwater
Estuary, 1978-1994". Report to National Rivers Authority
and English Nature. Cambridge Coastal Research Unit, University
of Cambridge.
English Nature (1992). "Campaign for a Living Coast".
English Nature, Peterborough.
EA (1996). "A Guide to the Understanding and Management
of Saltmarshes". R&D Note 324. Environment Agency.
HR Wallingford (1996). "Estuaries: the Case for Research
into Morphology and Processes". Report SR478.
MAFF (1993). "Strategy for Flood and Coastal Defence
in England and Wales". Ministry of Agriculture, Fisheries
and Food and the Welsh Office.
MAFF (1995). "Shoreline Management Plans—A
Guide for Coastal Defence Authorities". Ministry of Agriculture,
Fisheries and Food.
ANNEX B
ANSWER TO ADDITIONAL WRITTEN QUESTION
Question: Could you specify for us the changes to PAGN
you have proposed to MAFF to ensure environmental features are
properly considered in the appraisal process? Have you developed
new methodologies to tackle the problem of valuing wetlands and
their associated wildlife? What response have you had from MAFF
regarding possible amendment of PAGN to take your requests into
account?
Answer: We proposed changes to PAGN in the context of a recent
consultation exercise which did not address fundamental issues
such as MAFF's remit. Our suggestions were therefore limited to
proposals to improve PAGN within the constraints of MAFF's current
remit.
We made the following suggestions:
— That there should be better guidance on practical
techniques to include nature conservation in the appraisal.
— That there was a need for monitoring to ensure
that appraisals actually follow the published guidance.
— That appraisals should take account of the need
to look at an appropriately wide area in appraising the costs
and benefits of an individual scheme.
— That there was a need for specific guidance on
managed re-alignment.
These comments were based on our experience as a consultee
commenting on a substantial number of flood and coastal defence
schemes each year.
To date we have received a brief response from MAFF suggesting
that they feel the current document is essentially correct, except
for some anomalies.
English Nature has not itself developed new methodologies
for valuing wetlands and their associated wildlife. We are however
actively engaged in the debate about this subject. Most previous
attempts to value wildlife and natural assets have involved a
technique known as Contingent Valuation. This technique derives
a value from surveys in which members of the public are asked
to put a hypothetical value, that they would be prepared to pay,
on an environmental asset. English Nature takes the view that
there are severe practical and conceptual difficulties in applying
Contingent Valuation to natural habitats and wildlife.
English Nature is not entirely comfortable with the concept
of trying to put a cash value on the natural environment. However,
failure to do so often means that important natural assets are
given zero weight in appraisals.
The HM Treasury Green Book guidance, revised in 1997, approves
for use a variety of alternative valuation techniques, including
the following:
— Habitat Replacement Cost Valuation—This
uses realistic estimates of the cost of replacing the habitats
that would be lost (including elements such as land purchase,
engineering works and direct habitat manipulation) as a proxy
for society's willingness to pay for protecting the asset. Although
it can be argued that "replacement cost" is not the
same thing as "society's value", it can have a role.
It is particularly appropriate where the losses relate to sites
which will require actual replacement due to Government policy
or international commitments. Even where there is no explicit
commitment to replacement it may have a role where the habitat
is re-creatable.
— Multi-Criteria Analysis—This technique provides
a structure, either qualitatively or with scores and weights,
for bringing together effects that can be valued in money terms
with those that cannot. It is being used by DETR for road schemes
and by the Environment Agency in their appraisal of water quality
investment schemes.
— Descriptive information—This technique does
not apply any values to habitats or wildlife, but sets out the
environmental effects of a proposal in appropriate detail alongside
the cost-benefit data for other effects. The reader is then left
to make the necessary comparisons and trade-offs.
English Nature believes that these alternative valuation
techniques can be useful in certain circumstances, they should
be given emphasis in PAGN, and they should be more widely used
in practice. All of them would benefit from further development.
ANNEX C
ADDITIONAL EVIDENCE BY ENGLISH NATURE TO ILLUSTRATE
POINTS GIVEN IN
ORAL EVIDENCE
1. Figures to illustrate the unsustainability of the conventional
approach to flood and coastal defence in some areas (supplement
to English Nature's answer to question 432).
In Essex, total public expenditure on coastal defence of
agricultural land since the 1953 floods has been £200 million
at 1995 prices. This equates to an average of £14,000 per
ha defended. In the most difficult areas up to £60,000 per
ha has been spent. The true cost is higher as drainage of the
defended land was often also subsidised. The financial and physical
unsustainability of always maintaining current defended lines
by re-inforcing hard defences is well illustrated by a c. 1.5
km stretch of frontage known as Orplands, on the south bank of
the Blackwater Estuary (National Grid reference TL 990 073). Here
a section of flood bank defending a strip of low lying ground
one field wide had become exposed to wave action following loss
of the saltmarshes. This wall received continual maintenance,
costing many times the value of the land, until a managed re-alignment
scheme was implemented in 1996.
2. Could RDAs deliver river and coastal management? (supplement
to English Nature's answer to question 438).
English Nature does not favour this option. Regional Development
Agencies (RDAs) do not have expertise in this field, they suffer
from the major disadvantage that their boundaries do not match
the natural divisions of coastline and catchment and their focus
also seems likely to be on development, not environmental management.
We also feel that a national body with a strong and accountable
regional structure would be better placed to undertake the co-ordinated
and coherent delivery of a programme that meets both national
and local needs in an integrated and sustainable way. Such a body
would clearly need to work effectively with the RDAs, as well
as local authorities, interest groups and communities.
3. Additional examples of where local pressure has lead
to the choice of an unsustainable or environmentally damaging
option (supplement to English Nature's answer to question 442).
English Nature offered to provide additional examples. This
is a fairly common phenomenon, but we have two particularly acute,
current examples:
Seatown, West Dorset
In response to determined local lobbying the District Council
has promoted this scheme which comprises counterfort drains, cliff
toe protection and soil nailing of the cliff back scar, in order
to stabilise a landslip threatening three houses and a public
house. It is within the West Dorset Coast SSSI. The grant-eligible
cost is £408,000, and a cost over-run seems likely. The cost
benefit analysis relied heavily on the loss of the coastal footpath,
but re-routing was not explored as an option. There is unprotected
cliff on either side of this scheme and the long-term sustainability
of the protection must be in doubt as the unprotected cliffs continue
to erode. Non intervention would appear to be the only sensible
long-term policy.
Birling Gap, West Sussex
This cliff protection scheme is currently being proposed
for a section of eroding cliff within the Seaford to Beachy Head
SSSI to protect a car park, a hotel, six coastguard cottages and
a look-out point. This whole 8 km section of coastline is currently
unprotected and is the classic example of south coast white cliffs,
with the Seven Sisters immediately adjacent. Local protection
to this very limited developed area will cause significant damage
to the geological and coastal geomorphological interest of the
SSSI and to the coastal landscape. It is contrary to the local
plan and it may well accelerate the erosion of adjacent unprotected
cliffs. Coast protection at this location is not sustainable,
as in the long-term it will be outflanked as the rest of the cliff
line recedes. Non intervention is the only sensible course of
action in the long term. The coast protection scheme is being
promoted in response to a concerted local campaign lead by Lord
Harris and Lord Howie.
4. Evidence of the practicality and usefulness of managed
re-alignment as a technique and additional information on where
it is most likely to be of benefit (supplement to English Nature's
answer to question 461).
English Nature has, in partnership with other organisations
including MAFF and the Environment Agency, been involved in a
series of pilot managed re-alignment schemes. The first of these
was a small scheme covering 0.8 ha at Northey Island in Essex,
which was carried out in 1991. This was followed by a 20 ha experimental
scheme at Tollesbury, also in Essex which was carried out in 1995
and the operational scheme at Orplands referred to earlier. In
addition, English Nature commissioned a review of areas where
seawalls had failed in the past.
Although the experimental sites are still developing it is
possible to make a number of provisional conclusions about managed
re-alignment:
— The best sites for managed re-alignment are those
where long, thin strips of low-lying land are protected from the
sea by flood banks and are backed by naturally rising ground.
In locations like this it is possible to create varied, stable
saltmarsh and mudflat and to make signficant savings in maintenance
costs for a modest sacrifice of agricultural land.
— In the right places, managed realignment can make
a wider contribution to the sustainable management of estuaries.
— Managed re-alignment has signficant advantages
over non-intervention, where walls are allowed to fail. The results
from non-intervention do show a considerable degree of variation.
The picture that emerges to date is that managed re-alignment,
whilst not a panacea, is a useful and practical management technique.
Like all coastal management techniques it needs to be applied
where it is appropriate.
The draft Essex Shoreline Management Plan identified five
substantial management units where managed realignment was suggested
as the preferred option (though these recommendations did not
survive the process of formal adoption by the LFDC). These are
sections of coast where the area of low-lying ground is narrow
or where there is an obvious second line of defence. These areas
are representative of the locations elsewhere where we feel managed
re-alignment has a role. English Nature does not advocate large
scale managed re-alignment in areas such as The Wash where large
areas of low-lying, productive agricultural land are at risk.
Managed re-alignment in such cases will be limited to adjustments
to the defended line in order to improve the overall sustainability
of the defences. The North Sea Camp proposal referred to in our
written evidence is an example of such an adjustment.
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